Select Page
```1. 558.9 g of a nonelectrolyte are completely dissolved in sufficient water to make 2.50 L of an aqueous solution at 25.0oC. The osmotic pressure of the solution is 23.6 atm. What is the molar mass of the nonelectrolyte, in g/mol?
2. Sucrose is a nonvolatile, nonionizing solute in water. Determine the vapor pressure lowering, in torr, at 27.0°C, of a solution of 75.0 grams of sucrose, C12H22O11, dissolved in 1.80 x 102 g of water. The vapor pressure of pure water at 27.0°C is 26.7 torr. Assume the solution is ideal.

3.A chloroform solution of caffeine has a concentration of 0.0868 m . Calculate the molarity of the solution, mole fraction of caffeine, and % w/w of caffeine. The density of the solution is 1.523 g/mL.
molar mass of caffeine (solute)= 194.2g/mol
molar mass of chloroform, CHCl3, (solvent) = 119.4 g/mol
4. A solution is prepared by dissolving 17.0 g of NaCl in 85.0 g of H2O. Calculate the mole fraction of NaCl in the solution

6. A 6.05 M solution of an acid, HX, has a density of 0.892 g/mL. The acid, HX, has a molar mass of 42.00 g/mol. Determine the concentration of this solution in m (molality), XHX (mole fraction of HX), and % w/w (percent by mass). The solvent in this solution is water, H2 O.

7. A 0.4196 XHX (mole fraction of HX) solution of an acid, HX, has a density of 1.141 g/mL, and the molar mass of the acid is 28.22 g/mol. Determine the concentration of this solution in M (molarity), m (molality), and % w/w (percent by mass). The solvent in this solution is water, H2O.
8. Commercial concentrated aqueous ammonia is 28.0% NH3 by mass. The solution has a density of 0.900 g/mL. Calculate the molarity of the solution, molality of the solution, and mole fraction of NH3.
9. Use thermodynamics data in Appendix K of your textbook to calculate the enthalpy of reaction for
2FeS2(s) + (11/2) O2(g) ? Fe2O3(s) + 4SO2(g)
Be sure to enter the appropriate sign for your answer.
10. Use thermodynamics data in Appendix K of your textbook to calculate the enthalpy of reaction for
C2H6(g) + CH4(g) ? H2(g) + C3H8(g)
Be sure to enter the appropriate sign for your answer.
11. Determine the ?H0rxn for
C3H4(g) + 2 H2(g) ? C3H8(g)
using this information:
2 H2(g) + O2(g)? 2 H2O(?) ?H0rxn = -571.6 kJ/mol rxn
C3H4(g) + 4 O2(g) ? 3 CO2(g) + 2 H2O(?) ?H0rxn = -1937 kJ/mol rxn
C3H8(g) + 5 O2(g) ? 3 CO2(g) + 4 H2O(?) ?H0rxn = -2220 kJ/mol rxn
Do not forget to enter the appropriate sign, + or -.
12. Given this reaction and information:
4 H2(g) + CO2(g) ? CH4(g) + 2 H2O(g) ?H = -165 kJ/mol
suppose that 12.5 g of H2 react with 86.0 g of CO2. Answer the following questions about this reaction.
13. NH3(g) + Cl2(g) ? NH2Cl(g) + HCl(g)
Calculate the ?H (in kJ) for the above reaction.
Given the following Bond Energies (kJ/mol)
N-H 389
N-Cl 201
H-Cl 431
Cl-Cl 243
14. Which of the following hypothetical reactions MUST be endothermic? Assume all compounds are covalent compounds. 2 A2D(g) ---> 2 A2(g) + D2(g)
A2B3(g) ---> 2 A(g) + 3 B(g)
A(g) + B2(g) ---> AB2(g)
5 B(g) ---> B5(g)
B4(g) ---> 4 B(g)
Explain why.
15. If 6.824 kJ of heat is added to a coffee cup calorimeter containing 54.55 g of
H2O initially at 21.720oC and the water's temperature rises to 27.525oC, what is
the heat capacity, or calorimeter constant, for this calorimeter? The specific
heat for H2O is 4.184 J/goC.
16. Given this information about the generic chemical reaction:
3 A(g) + B(g) ? 2 C(g) + D(?) ?H0rxn =-629.3 kJ/mol
What are the values of w, q, and ?E0rxn for this chemical reaction at constant temperature (298 K) and pressure?
Also choose the appropriate responses for each Choose Box.
Be sure to enter the appropriate sign with each answer.
17. A coffee cup calorimeter is used to measure the heat of neutralization for this acid-base reaction.
HBr(aq) + NaOH(aq) ? NaBr(aq) + H2O(?)
35.0 mL of 0.250 M HBr are reacted with 60.0 mL of 0.325 M NaOH. Both solutions are initially at 20.500oC. After the reaction has finished, the temperature of the mixture is 21.640o C. The heat capacity of the calorimeter is 28.7 J/oC and the specific heat of the mixture is 4.184 J/goC. The density of the solution is 1.02 g/mL. Use the information given above to answer the following questions.
(Number of moles must have 3 significant figures when it is used to calculate the heat of neutralization. Include the appropriate "+" or "-" sign for heat of neutralization.)

18.) Consider the following reaction at constant pressure. Which response is true? N2(g) + O2(g) --> 2NO(g)
a. Work may be done on or by the system as the reaction occurs, depending upon the temperature.
b. Work is done on the system as it occurs.
c. The amount of work depends on the pressure.
d. Work is done by the system as it occurs.
e. No work is done as the reaction occurs.
Explain why it is true.
Additional Requirements

Level of Detail: Show all work
Other Requirements: Please show all work and explain steps and rationale for choosing multiple choice answers. Thank you.

Dear Student, I have added and revised Question numbers 5, 9, 12, 14 and 17. In question number 9, different books follow different tables and thus values of enthalpy of formation of compounds are different in different books. I have used two different values and calculated and thus have provided two answers. I hope one of them should be correct. If you can provide me Appendix K of your book then I will be able to calculate according to those values. I have tried to answers all the questions as correctly as possible. If there is any problem, do let me know and I will try to help you to the best of my knowledge. Do let me know if you are satisfied or not and I will be happy to help you. Thank you!```